The present invention relates to systems to connect one or more central computer or communications processor to a plurality of peripheral devices, as part of a communications or data processing network. Systems currently in use utilize multiple redundant connections in order to ensure continuing communications between the central processor and the peripheral devices even if failures or errors occur in the communications. Some such systems also include error-checking means or methods, such as processing means or systems included as part of the peripheral devices, these processing means or systems are equipped to check signals arriving from the central processor and to transmit back to the central processor information indicating whether the information has been received correctly. An need exists to improve the connection and error-checking means, in order to provide reliable communications between the central processor and the peripheral devices at substantially lesser cost, and in substantially more physically compact form, than systems currently in use.